Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Qual foi a forma de partida para a data da vaga de 20 de setembro de 2009?
 ###Tabelas: CREATE TABLE runners-up_12 (runners-up_12_id AUTO_INCREMENT PRIMARY KEY, Date VARCHAR, Tournament VARCHAR, Surface VARCHAR, Opponent in the final VARCHAR, Score VARCHAR) CREATE TABLE 2013_teams (2013_teams_id AUTO_INCREMENT PRIMARY KEY, Team VARCHAR, Home city VARCHAR, Home ground VARCHAR, In Toppserien since INT, First appearance INT, Seasons INT) CREATE TABLE managerial_changes (managerial_changes_id AUTO_INCREMENT PRIMARY KEY, Team VARCHAR, Outgoing manager VARCHAR, Manner of departure VARCHAR, Date of vacancy VARCHAR, Replaced by VARCHAR, Date of appointment VARCHAR, Position in table VARCHAR) CREATE TABLE u.s._metropolitan_areas_with_large_indian_american_populations (u.s._metropolitan_areas_with_large_indian_american_populations_id AUTO_INCREMENT PRIMARY KEY, Rank INT, Metropolitan Statistical Area VARCHAR, Total Population (2010) INT, Indian American Population (2010) INT, % Indian American VARCHAR, Asian American Population (2010) INT, % Asian American VARCHAR, Combined Statistical Area VARCHAR) CREATE TABLE punjab (punjab_id AUTO_INCREMENT PRIMARY KEY, Serial No. INT, District VARCHAR, Headquartered City VARCHAR, City Population (2009) INT, City Area(km 2 ) INT)  
SELECT Manner of departure FROM managerial_changes WHERE Date of vacancy = 20 september 2009